Referring to FIG. 1, a conventional touch-screen electronic device usually has a text area 110 that displays input text or a popup message and a keyboard area 120 allowing a use's text input. In addition, an area 130 which presents candidate words will also generally appear around keyboard area 120 during the user's input. In order to achieve an optimal balance between screen usage efficiency and the user's visual experience, area 130 is typically disposed on top of keyboard area 120 and is so configured that the candidate words are laterally arranged one by one. The conventional touch-screen input techniques allow for selection of only one word by a single input (defined hereinafter as a touch that a finger or an input instrument, such as a stylus, makes since it comes into contact with the screen until it leaves the screen). For example, in such techniques, a tapping or other motion is allowed to cause the input of a single word, and even with a conventional touch-screen keyboard which allows text input by sliding trajectories, a sliding trajectory completed in one motion can only be parsed as one word. This leads to a great reduction in information input efficiency, increased operating complexity, and significant user inconveniences. Therefore, there is a great need in the field of information input to touch-screen electronic devices for enabling the input of a sequence of words or a complete sentence through a single input.